A code is usually used when information has to be passed on together with an object. If the object is automatically handled in any manner, then machine-readable codes are typical. Codes that can be read out optically are useful because the codes can typically be inexpensively and rapidly produced by printing processes. Simple machine-readable symbols comprise fields having a sufficiently high contrast between them. Whereas a single black or white field only has an information content of 1 bit, the necessity of having to make larger amounts of information machine-readable led to the development of so-called barcodes. These are lines or bars which, in a defined width and with a defined spacing between each other, can code a certain limited amount of data. The need for transmitting larger amounts of data led to the development of two-dimensional codes (2D-codes). These differ with regard to the amount of data, the size, the necessary contrasts and the requirements with regard to printing quality or reading performance. In the field of analytics such information carriers can be used to provide lot-specific information such as the relationship between analyte and measurement signal in a machine-readable manner. An example of this is the test strip drum of the ACCU-CHEK® Compact blood glucose measuring system available from the Applicant hereof on which a barcode containing test-specific information is provided on the drum and automatically read out, such as is described in DE 10360786, the disclosure of which is hereby incorporated by reference herein in its entirety.
In this context, the object of the present invention is to further improve the means and systems known in the prior art and in particular to ensure a reliable coding and evaluation using simple means.